We propose to undertake resource-related research into the develo]ment of methodologies that will permit dissemination of high performance clinical consultation and data management systems. We have developed a prototype system which provides a framework for the execution of clinical trials. Our goal is to extend this model to a broader range of investigators, including those in both academic and community settings. The initial system, named ONCOCIN, was developed on the SUMEX-AIM Resource at Stanford University and is designed to help oncologists manage patients enrolled in experimental cancer chemotherapy protocols. In its initial three years, the research has focused on theoretical computer science issues regarding the representation of medical knowledge and the development of optimal methods for encouraging the use of computer-based tools by physicians. The prototype system has been introduced for limited use in our oncology clinic. Our goal is to allow systems like ONCOCIN to function independently, on their own hardware, so that they can become useful tools for clinical investigators in a variety of research settings. We propose a five-year effort with the following specific aims: (1) to transfer the oncology prototype from its current research computer to a powerful professional workstation that provides a model for the technology that will soon allow large scale cost-effective dissemination of clinical consultation systems; (2) to encode and implement for use by ONCOCIN the commonly used chemotherapy protocols from our oncology clinic; (3) to introduce ONCOCIN gradually for ongoing use so that two professional workstations become available in the oncology clinic to assist in the management of patients enrolled in cancer clinical trials; (4) to implement ONCOCIN beyond the Stanford environment to demonstrate the transferability of the technology and its potential for involving community physicians in clinical investigation; and (5) to develop and test methods for assessing the impact of this kind of tool on physicians, and on their modes of practice.